Igititioh system fob intebjstal-combustioht bjstgihes



I w. F. STRAND. IGNITION SYSTEM FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED MAR. I8, I919.

Patented Apr. 13, 1920.

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'WILLIAM F. STRAND, OF DES MOINES, IOWA.

Specification of Letters Patent.

Patented Agr. 113, race.

Application filed March 18, 1915*. Serial No. 283,403.

construction.

More particularly it is my object to provide a device for normally opening the low tension circuit of a timing device except at theinstazit that the high tension circuit is closed through the spark plugs of the engine.

A further object of my invention is to provide means whereby the closing of the low tension circuit may be accomplished by a cam attached to the shaft which carries the circuit closing device for the high tension circuit.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of the device, whereby th objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawin s, in which:

Figure 1 shows a plan view of my improved device, with the upper half of the casing removed.

Fig. 2 shows a central, vertical, sectional view, taken on the line 2--2 of Fig. 1.

F ig. 3 shows a. detail view of a part of my invention; and

Fig. 4 shows a detail of another part of my invention.

Referring to the accompanying drawings, I have used the reference numeral 10 to indicate half of the casing for my timing device, and the reference numeral 11 to indicate the other half, which is similarly shaped and secured thereto by means of screws 12, The portion 10 of the casing has a bearing member 13 disposed centrally thereof. and designed to receive the shaft 14,

.which may be an extension of the cam shaft of the motor or connected therewith to revolve at the proper speed;

The shaft 1 L is rotatably but nonslidaolyv mounted in the bearing 13 by means of an annular flange 15 which is received within the casing, and a collar 16 which may be secured in place on the shaft 'outside the casing as by means of screws 17.

Adjacer; to the flange 15 the shaft 14 has an in-turned shoulder 18, having a roughened face. Extending from the shoulder 11% the shaft is contracted 'at 19 and again contracted at 20, the latter portion being externally screw-tln'eaded.

Received on the contracted portion 19 is a cam 21 provided with points 22 which equal in number the number of cylinders which the engine has to which the timer is at tached. The cam 21 is provided with roughened surface or face designed to coact with the roughened surface of the shoulder 18.

A washer 23 has a screw-threaded opening therein, designed to coact with the threads on the contracted-portion 20 and to hold the cam 21 against the shoulder 18. It will thus be seen that by means of the roughened sur faces on the cam 21 and the shoulder 18 and the washer the cam 21 maybe locked in any position relative to the shaft Li.

A contact arm 2% extends laterally from the end of the shaft H and is secured thereto by means of a vertical portion 25 having an internally screw-threaded opening therein designed to coact with the threads on the contracted'portion 20. The arm 24 is composed of non-conducting material and is provided on its upper surface with a strip of conducting material 26, and contact points 27 and 28 are disposed at the ends of the strip 26.

Binding posts 29 are secured in the casing member 11 in position spaced from each other and in position to coact with the contact 27 to close the high tension circuit through the spark plugs of the engine. The contact 28 is connected with the secondary circuit of the coil of the ignition circuit by means of the binding post 30.

It will thus be seen that the revolution of the arm 2-l will successively place the contact 27 in position to close the circuittln'ough the binding posts-E29. device shown, the contact 27 is moved to position approximately one-thirty-secoml of In the form of the an inch from the contact points 31 at the base of the binding post 29. so that the circuit is closed by means of a spark which jumps across between the contacts 27 and 31.

A support 232 is mounted in the casing member 10 and carries a tlat spring 233 which projects to position to coact with the points 22 on the cam 21. A stop bracket 34 is also secured to the support 32. and normally bears against the spring 33 at a place inten mediate of the ends oi the spring.

Adjacent to the support 32 a binding post 35 is secured to the casing 10 and extends therctlu'ough. \Vashers 6 or other suitable means are provided to insulate the binding post 35 from the casing 10. The binding' post 35 provided with a slidablc contacting member 37 which may be seoured from movement by means of a tightening screw 38. In the form shown, the binding post is split down part way adjacent to the opening which receives the slidable contact 37, so the tightening oi the screw 38 tightens together the split portions of the binding post, thereby 't'ric tionally engaging the sliding member 37.

Means are provided for adjusting the relative position of the spring 323. comprising slots 35) which receive thc screws it), so that by loosening the screws ll) the spring 33 may be moved longitudinally.

The binding post 35 is connected by any suitable means. as by a wire -11. with the source of low tension electrical energy.

in the practical operation ol my improved device the parts are installed as shown iu'l igs. l and :2 of the drawing. in position where the shaft It may be connected with the engine to so rotate the' shaft that the contact 27 will successively close a circuit through the contacts 31; at the proper time to tire the explosive charges in the cylinders. The cam 21 is then adjusted to such position.rclative to the spring- 33 that the points will suecessively contact with the spring to bend the spring on the stop 34 just prior to the time that the, contacts 27 and 31 are adjacent to each other.

they first flex the spring 33 and then release it, whereby the spring 33 rebounds to position Where it contacts with the sliding contact member 37.

The adjustment of the positions of the cam 21, the spring 33 and the sliding contact member 37 must be such that the rc bound of the sprin will occur at the instant that the spark should pass between the contac' QT and the adjacent contact 31.

Trom the 'loregoing it will be seen that the low tension circuit of the ignition system for the engine will be open at all times exceptat the instant when the spark in the cylinders should occur.

The advantages of this arrangement: which As the points 22 revolve I have termed auto-mcchanical will be obvious from the ioregoing description of its operation.

'Some changes may be made in the details of the structure and arrangement of my device, without departing from the essential purpose of my invention. and it is my intention to cover by my claims any modified forms of structure or use. of mechanical equivalents which may be reasonably included within their scope.

I claim as my invention:

1. In a multiple cylinder internal combustion engine ignition system comprising a low tension circuit. a high tension circuit. and means for successively closing the high tension circuit through each of a plurality of contacts connected with the ignition de' vices of the respective cylinders. a support. a stop bracket secured thereto. an elongated flat resilient conduetm having one end secured to the support and adapted to normally yieldingly bear against the stop in tcrmodiatc of the ends of the comluctor, a contact secured to the conductor between the free end. thereof aml the. stop. a. second contact secured to the support in position spaced from the first contact. means for adjusting the distance of the second contact from the first. and means operated by the first described means for flexing the coir ductor against the stop somewhat prior to the closing of the circuit through each of the first described contacts. whereby the rebound of the conductor will bring the two last described contacts togethcr for an inslant.

2. In a multiple cylinder internal combustion engine ignition system comprising a low tension circuit. a high tension circuit, and means tor successively closing the high tension circuit through each of a plurality ol contacts connected with the ignition devices oi the respective cylinders. a support, a. stop bracket secured thereto. an elongated llat resilient conductor havingone end cured to the support and adapted to normally yieldingly bear against the stop intcrmcdiate of the ends of the conductor, a contact secured to the conductor between, the tree cud thereof and the stop, a second contact secured to the support in position spaced from the first contact. and means for flexing the conductor against the stop somewhat prior to the closing of the. ciruit through each of the first described contacts. \vhcreby the rebound of the conductor will bring the two last described contacts ingly press against a stop, a stop dispssed intermediate of the ends of said re imen; device. a Contact spacedfrom said device and disposed on the side thereof oppos ite said stop and means for flexing said spring on the stop prior to the closing of the nigh tension circuit and for releasmg said sp ing at the in n51 n 0 111 3 high tension circui'fi Q-iOSEd, whereby the spring may lCQOlllld againsa said contact to thereby siinuii'm 10 neously close the low tension circuit.

Des i iioines iowa March 8, 1919.:

WILLIAM F. STRAND. 

